JPH04289087A - Robot device - Google Patents

Abstract

PURPOSE:To facilitate the work at the time of holding a work with a robot and giving instruction in the then position and posture of the robot. CONSTITUTION:In the respective grips 3a, 3b of a robot hand 2, there are respectively provided distance sensors 14a, 14b which measure a distance between the respective grips 3a, 3b and a work 7. A distance between the respective grips 3a, 3b and the work 7 is measured with the distance sensors 14a, 14b if the center of the hand 2 does not coincide with that of the work 7 as shown in Fig. 6(a). As a result, the compensating position of the hand 2 is calculated, and as shown in Fig. 6(b), the position of the hand 2 is compensated. Then, as shown in Fig. 6(c), holding work is carried out in a condition where the center of the hand 2 coincides with that of the work 7. It is thus possible to provide the data of the then position and posture as teaching information.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a robot device equipped with a hand for gripping a workpiece, and more particularly to a robot device that can easily perform a teaching operation for gripping the workpiece.

0002

2. Description of the Related Art FIG. 7 is a configuration diagram showing a conventional robot device. In the figure, 1 is a robot body, 2 is a hand fixedly attached to the tip of the robot body 1, and 3a and 3b are hand 2. 4 is a control device that drives the robot body 1; 5 is a control device that drives the robot body 1;
is connected to the control device 4, and the robot body 1 and hand 2
This is a teaching device for manual operation.

FIG. 8 is a diagram showing the basic operation of the two grips 3a and 3b that make up the hand, and the grips 3a and 3b, which are in the open state, move symmetrically,
Each moves to the closed position shown at 30a and 30b, and reciprocates between the two as the opening and closing operations occur. At this time, the operating stroke of each grip is the grip 3 in the open state.
The stroke L between a and 3b is half L/2.

Next, the operation will be explained with reference to FIG. In FIG. 9, 6 is a pallet provided with holes for inserting works such as pins, and 7 is works such as pins inserted into the holes of the pallet 6. First, FIG. 9(a) shows the hand 2 positioned above the workpiece 7 with the grips 3a and 3b open. At this time, the center of the hand 2 and the center of the workpiece 7 do not coincide with each other, and the distances between the grips 3a, 3b and the workpiece 7 are La and L, respectively.
b and are not equal. This kind of situation always occurs during robot teaching work, and the worker usually does not use the teaching device 5.
While operating the hand 2 to move the position of the hand 2 and visually operating the hand 2 so that their centers coincide with each other, when the centers coincide with each other, input data regarding the position and posture as teaching information via the teaching device 5. However, it is difficult to match them completely.

FIG. 9(b) shows a situation when, for example, the teaching device 5 is operated in such a state to close the grips 3a and 3b. At this time, the grips 3a and 3b operate symmetrically, so the grip 3a comes into contact with the workpiece 7 first, and then the grip 3b comes into contact with it. In the end, the rigidity of the robot 1 is generally higher than that of the workpiece 7 and pallet 6.
As shown in FIG. 9(c), the hand 2 moves slightly toward the grip 3a and comes to rest.

Next, the case where the workpiece 7 is in a free state will be explained with reference to FIG. In FIG. 10, 8 is a flat surface plate with little friction, and the workpiece 7 is placed freely on this surface plate 8. Similar to FIG. 9(a), FIG. 10(a) shows the hand 2 positioned above the workpiece 7 with the grips 3a and 3b open, and the center of the hand 2 and the center of the workpiece 7 are not consistent with each other. Figure 10(b) shows the grip 3a in this state.
, 3b are closed. Since the grips 3a and 3b move symmetrically, the grip 3a first touches the workpiece 7.
come into contact with. At this time, the workpiece 7 receives a force from the grip 3a, so it slides on the surface plate 8 until the grip 3b on the opposite side comes into contact with the workpiece 7. And finally, Figure 9 (
As shown in c), the robot 1 comes to rest in a state where the rigidity is balanced by the frictional force between the workpiece 7 and the surface plate 8.

[0007]

[Problems to be Solved by the Invention] Since the conventional robot device is configured as described above, the hand 2 and the workpiece 7
If the grips 3a and 3b are closed when the positions of cannot perform teaching tasks. Further, after the grips 3a and 3b are closed, it is unclear which side the hand 2 is biased toward the workpiece 7. On the other hand, in a case like FIG. 10 where the workpiece 7 is not fixed,
Since the workpiece 7 is moved, a problem occurs when trying to teach the initial position of the workpiece 7. In either case, delicate operation of the teaching device 5 is required to perform accurate teaching work, and this operation requires a great deal of time and experience. There are some systems in which a sensor such as a load cell is provided between the hand 2 and the robot 1 to detect the reaction force from the workpiece 7 and perform a correction operation, but this method has the drawback of being expensive.

[0008] This invention was made to solve the above-mentioned problems, and it is possible to perform teaching work in a short time with simple operations, and to obtain accurate teaching information without performing precise teaching work. The purpose is to obtain a robot device that can automatically obtain the following.

[0009]

[Means for Solving the Problems] A robot device according to the present invention includes a hand having a plurality of grips for gripping a workpiece, and is capable of reproducing the hand according to the teaching of the position and posture of the hand. a display section comprising a contact sensor provided on each of the grips and detecting a contact state between each of the grips and the workpiece; and a display element that displays the state of contact between each of the grips and the workpiece; and a signal generating section that determines the order in which the output signals of the contact sensor are generated and outputs a signal to at least the display element corresponding to the grip in which the contact state occurs first.

[0010] Furthermore, a robot device according to another aspect of the present invention is provided with a hand having a plurality of grips for gripping a workpiece, and is capable of reproducing the hand according to the teaching of the position and posture of the hand. In the product, a sensor is provided on each grip to detect the distance or angle between each grip and the workpiece, and the relative position of the workpiece and each grip is determined based on the output signal of each sensor. and a position correction section that generates a signal for correcting the position and posture of the hand based on the output signal of the distance calculation section.

[0011]

[Operation] In this invention, the contact state between each grip and the workpiece is detected by a contact sensor, and the signal processing unit determines the order in which the detection signals are generated, so that at least the grip in which the above-mentioned contact state occurs first is detected. A signal is output to the display element of the display unit to clearly indicate the position of the hand.

In another aspect of the present invention, the distance or angle between each grip and the workpiece is detected by a sensor, and the distance calculation section calculates the relative position between each grip and the workpiece based on the detection signal. Calculate,
A position correction unit generates a signal for correcting the position and posture of the hand from the calculated relative position, and corrects the positional relationship between the hand and the workpiece.

[0013]

[Example] Example 1. An embodiment of the present invention will be described below with reference to the drawings. Figure 1
is a configuration diagram showing a robot device, and in the same figure, 9
is a signal processing unit that determines the generation order of the output signals of the contact sensor, which will be described later, and the same reference numerals as in FIG. 7 showing other conventional examples indicate the same or corresponding parts, so the explanation thereof will be omitted. .

FIG. 2 is a diagram showing details of the hand 2 shown in FIG. 1, in which 11a and 11b are respectively incorporated into grips 3a and 3b, and
A contact sensor 1 detects the contact state between the workpiece 3b and the workpiece 7.
0a and 10b are LEDs respectively provided on the main body of the hand 2 and corresponding to a display section for displaying the output signal of the signal processing section 9.

Next, the operation will be explained with reference to FIG. In FIG. 3, 6 is a pallet provided with holes for inserting works such as pins, and 7 is works such as pins inserted into the holes of the pallet 6. First, FIG. 3(a) shows the hand 2 positioned above the workpiece 7 with the grips 3a and 3b open. At this time, the center of the hand 2 and the center of the workpiece 7 do not coincide with each other, and the distances between the grips 3a, 3b and the workpiece 7 are La and L, respectively.
b and are not equal.

FIG. 3(b) shows the situation when, for example, the teaching device 5 is operated in such a state to close the grips 3a and 3b. Since the grips 3a and 3b operate symmetrically, the grip 3a contacts the workpiece 7 first, and the grip 3a
A signal from the contact sensor 11a incorporated in the sensor is input to the signal processing section 9. After that, the grip 3b is also attached as shown in Fig. 3(C).
As shown in FIG. 3, the signal from the contact sensor 1b that comes into contact with the workpiece 7 and is built into the grip 3b is also delayed and sent to the signal processing section 9.
is input. The signal processing unit 9 determines the input order of these two signals, and in this example lights up the LED 10a corresponding to the contact sensor 11a that detected the contact earlier. Therefore, by knowing which LED is lit, it is possible to know the positional relationship between the hand 2 and the workpiece 7.

In this case, the LED 10a lights up, indicating that the hand 2 is on the right side as shown in FIG. Therefore, by operating the teaching device 5, the operator can once open the hand 2, turn off the LED 10a, and then move the hand 2 slightly to the left to improve the degree of matching than before. When a suitable position and posture are repeatedly obtained, data regarding these are inputted to the teaching device 5 as teaching information, and the teaching work is completed.

Note that in the above embodiment, the LEDs 10a, 10
Although the case where b is provided in the hand 2 portion is shown, the same effect as in the above embodiment can be obtained even if it is provided in a portion other than the hand 2 portion, such as the teaching device 5.

Further, in the above embodiment, the contact sensor 11a,
The case has been described in which the LEDs 10a and 10b are turned on when the contact state of the contact sensor 11b with the workpiece 7 is first detected. If the input time interval is less than or equal to a preset value, the LEDs 10a and 10b
It is also possible to display that the amount of positional displacement between hand 2 and workpiece 7 is within the permissible range by lighting both of them.Also, if an air hand is used as hand 2, Since the operating speeds of the grips 3a and 3b differ depending on the pressure difference, in such a case, if the preset value is made changeable, the same effect as in the above embodiment can be achieved.

Example 2. Next, another embodiment of the present invention will be described with reference to the drawings. FIG. 4 is a configuration diagram showing the robot device. In the figure, 12 is a distance calculation unit that calculates the relative position between the grips 3a, 3b and the workpiece 7 from the output signal of a distance sensor, which will be described later, and 13 is a distance calculation unit. This is a position correction unit that generates a correction signal for correcting the position and posture of the hand 2 from the output of the hand 2. The same reference numerals as in FIG. 7 showing other conventional examples indicate the same or corresponding parts. The explanation will be omitted.

FIG. 5 is a diagram showing details of the hand 2 shown in FIG. 4, in which 14a and 14b are respectively incorporated into the grips 3a and 3b, and the grips 3a,
The distance sensor is a sensor that detects the distance between the workpiece 3b and the workpiece 7 using, for example, light or the like in a non-contact manner.

Next, the operation will be explained with reference to FIG. In FIG. 6, reference numeral 8 denotes a flat surface plate with little friction, and the workpiece 7 is placed freely on this surface plate 8. First, FIG. 6(a) shows a state in which the hand 2 is positioned above the workpiece 7 with the grips 3a and 3b open. At this time, the center of the hand 2 and the center of the workpiece 7 do not coincide with each other, and the distances between the grips 3a, 3b and the workpiece 7 are La and Lb, respectively, and are not equal.

Next, operate the teaching device 5 to adjust the distance sensor 1.
4a, 14b to measure the distance between the grips 3a, 3b and the workpiece 7. This distance sensor 14a, 1
The output of the grip 4b is input to the distance calculation section 12, where the relative positional relationship between the grips 3a, 3b and the workpiece 7 is determined. Further, the output of the distance calculation section 12 is input to the position correction section 13, where correction signals for the position and orientation of the robot are obtained and fed back to the control device 4. As a result, the robot 1 uses the hand 2 based on this correction signal.
As shown in FIG. 6(b), the grips 3a,
It comes to rest at a position where the distance between 3b and work 7 is equal. Therefore, as shown in FIG. 3(c), when the teaching device 5 is operated again in this state to close the grips 3a, 3a, the workpiece 7 placed on the surface plate 8 does not slip, and the grips 3a, 3a close.
3b. Thereafter, the data regarding the position and posture at this point is inputted to the teaching device 5 as teaching information,
Finish the teaching work.

[0024] In the above embodiment, the grips 3a, 3b
The case where the distance sensors 14a, 14b are used to detect the distance between the grips 3a, 3b and the workpiece 7 has been described.
If the sensor also has the function of detecting the angular displacement between the grips 3a and 3b and the workpiece 7, even if the inclinations of the grips 3a and 3b and the hand 2 do not match, the grips 3a and 3b
Accurate teaching information can be obtained by correcting the angular displacement between the workpiece 7 and the workpiece 7, and the same effects as in the above embodiment can be achieved.

Note that in each of the above embodiments, the grips provided with the contact sensors 11a, 11b or the distance sensors 14a, 14b are described in terms of two grips 3a, 3b, but the grips are not limited to this. For example, the structure may be such that the workpiece 7 is surrounded from the periphery like three claws, or the gripping method may be gripping from the inside depending on the type of the workpiece 7, but the same effect as in the above embodiment can be obtained. play.

[0026]

As described above, according to the present invention, the contact state between each grip and the workpiece is detected by a contact sensor, and the order in which the detection signals are generated is determined by the signal processing section, so that at least the above contact state is detected. The structure is configured to clearly indicate the position of the hand by outputting a signal to the display element of the display unit corresponding to the first grip that occurs, making it possible to perform teaching tasks in a short time with simple operations without requiring any skill. The effect is that you get what you can.

According to another aspect of the present invention, the distance or angle between each grip and the workpiece is detected by a sensor, and the distance calculation section calculates the relative position between each grip and the workpiece based on the detection signal. The correction unit generates a signal for correcting the position and posture of the hand from the relative position calculated above, and corrects the positional relationship between the hand and the workpiece, so precise teaching is possible. This has the effect that accurate teaching information can be automatically obtained without any work.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a robot device showing an embodiment of the present invention.

FIG. 2 is a detailed view of a hand showing an embodiment of the present invention.

FIG. 3 is a diagram showing a procedure for gripping a workpiece inserted into a hole with a hand having a contact sensor according to an embodiment of the present invention.

FIG. 4 is a configuration diagram of a robot device showing another embodiment of the present invention.

FIG. 5 is a detailed view of a hand showing another embodiment of the present invention.

FIG. 6 is a diagram showing a procedure for gripping a workpiece placed on a surface plate with a hand having a distance sensor according to another embodiment of the present invention.

FIG. 7 is a configuration diagram of a conventional robot device.

FIG. 8 is a diagram illustrating the operation of a conventional grip.

FIG. 9 is a diagram showing a conventional procedure for gripping a workpiece inserted into a hole with a grip.

FIG. 10 is a diagram showing a procedure for gripping a workpiece placed on a conventional surface plate with a grip.

[Explanation of symbols]

2 Hand 3a Grip 3b Grip 5 Teaching device 7 Work 9 Signal processing section 10a LED 10b LED 11a Contact sensor 11b Contact sensor 12 Distance calculation section 13 Position correction section 14a Distance sensor 14b Distance sensor

Claims (2)

[Claims] Claims: 1. A robot device comprising a hand having a plurality of grips for gripping a workpiece, and capable of reproducing the position and posture of the hand according to instructions thereof, wherein each grip is provided with: A display unit includes a contact sensor that detects the contact state between each of the grips and the workpiece, a display element that displays the contact state between each of the grips and the workpiece, and a display unit that detects the order in which output signals of the contact sensor are generated. A robot device comprising: a signal generation unit that makes a judgment and outputs a signal to the display element corresponding to at least the grip in which the contact state first occurs. 2. A robot device comprising a hand having a plurality of grips for gripping a workpiece, and capable of reproducing the position and posture of the hand according to instructions thereof, wherein each grip is provided with: a sensor that detects the distance or angle between each of the grips and the workpiece; a distance calculation section that calculates the relative position of the workpiece and each of the grips based on the output signal of each of the sensors; Based on the output signal of
A robot device comprising: a position correction section that generates a signal for correcting the position and posture of the hand.